A wireless network that provides wireless communications services to a large number of subscribers over a large geographic area, typically comprises a large number of wireless access points dispersed over the geographic area. Mobile computing devices (i.e., wireless devices), such as mobile telephones, laptop computers, tablet computers, and the like, connect to an access point to gain access to the network. Each wireless access point is typically associated with and in communication with a regional wireless access gateway. Each wireless access gateway may support a number of wireless access points in the network. The wireless access gateway is responsible for assigning Internet Protocol (IP) addresses and establishing IP sessions for wireless devices that connect to the network via one of the wireless access points that the wireless access gateway serves. In the past, when a wireless device “roams” from a wireless access point served by a first wireless access gateway to another wireless access point that normally is served by a second, different wireless access gateway, the current IP session of the wireless device must be terminated and a new session started by the second wireless access gateway. This sort of session interruption is disruptive to the user of the wireless device.
One technique for avoiding such IP session interruption involves the new wireless access gateway tunneling back to the home wireless access gateway to preserve the current session and the original IP address allocated to the wireless device. But this approach may be resource intensive and may consume valuable bandwidth in the network. Improved methods and systems for maintaining IP session continuity during wireless device roaming is desirable.